Mark Zuckerberg, Eduardo Saverin, Dustin Moskovitz, and Chris Hughes, all of who were students at Harvard University, founded Facebook in February 2004. The name “Facebook” comes from the colloquial name for the book given to students by some university administrations to help them get to know one another.

As the world’s most popular social network, there are over 1.15 billion users on the website. However, many people aren’t aware of how many features Facebook actually hides from their users. For example, have you ever heard of Facebook’s secret “Other” folder?

Recently, a report about a second folder for private messages hidden in the inbox was released, and many Facebook users were shocked to find out about this hidden folder, which can be found by opening your “Messages” and clicking on the “Other” tab next to the “Inbox.”

The hidden folder was intended to avoid spam and unwanted messages, but in many cases, the folder actually contained important messages. Thankfully, that secret folder is now public information.

There are still many other things about this popular social media website that you probably weren’t aware of, such as:

  • Saving Your Data

Go to Account Settings, and the bottom of the general options; you’ll find a link that says, “Download a copy of your Facebook data.” Once you’ve done this, Facebook will generate a report, which documents everything, you’ve shared, from photos to chat history. You’ll be surprised how much Facebook actually knows about your personal life.

  • The Removing or Hiding Option Doesn’t Remove Anything

One of the biggest misconceptions is that once you’ve hidden or removed something on Facebook, it’ll disappear. However, regardless of whether you’ve deleted, hidden, untagged, or removed something, Facebook is keeping a record of it. Have you ever noticed when you type a letter in the search box, the people you interact with most appear first? That’s because it’s arranged according to the people with whom you most commonly interact. In order to do this, Facebook needs to keep track of every chat, like, photo tag, and poke.

  • An Even Stronger Presence on Your Mobile Device

The Facebook Home for Android forces users to actually exit the app in order to view the rest of the items on their device. In addition, Facebook Home makes your friends visible at all times, with their status and photo updates immediately visible once you’ve unlocked your phone.

  • Keeping Track of Your Online Activity

Believe it or not, Facebook is watching you. While you’re signed in and browsing, Facebook actually keeps track of every site you’re visiting that has a Like or Share button, regardless of whether you’ve clicked it or not. Does the idea of being tracked online bother you? Simply log out of Facebook while you’re surfing the web.

  • A Searchable Personal Life

Everything you’ve ever shared on Facebook, from favorite books to sexual orientation, has been indexed and can easily be searched with Facebook Graph Search. Instead of going through someone’s “About” page, Graph Search allows users to dig up personal information on people. Feeling skeptical about this? Try searching “Friends who like [insert language here].”

If you weren’t concerned about your privacy on Facebook before, hopefully you’re a bit more aware of what to be concerned about now. To ensure a bit more privacy on Facebook, never share your Facebook password with anyone, and always think before you post.

It’s also a good idea to adjust your privacy settings on a regular basis, and only accept friend requests from people you personally know. If something looks suspicious, don’t hesitate to report it.